In previous types of transportation systems, such as, in high speed railway and/or mass and rapid transit operations, the equipment included a portion called a "H-1 Electronic Unit", which functions to interpret electrical and pneumatic input signals and converts these signals into electrical output signals required for the control of service brake, wheel slip control, annunciation, and certain malfunction indications. The H-1 electronic unit included a watchdog timer which is designed to monitor the operation and condition of the equipment. In the past, the watchdog timer did not work with or control the dump valves of the braking system of the railway vehicle. In practice, the conventional safety timer normally was a standard five (5) second timer which consisted of an R-C network and an electromagnetic relay. This type of approach appeared to be adequate when the control system was relatively simple and unsophisticated. However, upon further review and testing, it was found that this former safety timer was inadequate in that the timer could erroneously be placed in a reset condition by a table enable timeout or by an application pulse which is used during a slip correction which can create a condition of extended release of the brake cylinder pressure. Such an inadvertent reset is unacceptable in the present sophisticated state-of-the-art safety timers.